Need help -Jeep feels sluggish after locker install

[Trailboss]

Im hoping you guys can help me diagnose what is going on with my XJ. I have a 2000 with 85K on it. I installed an Aussie locker in my D30 last month as well as new hubs and axle u-joints. As soon as I got it back on the road I noticed that the car felt sluggish as if something were holding it back. Gas mileage has gone way down... 8-9 mpg. I took the Jeep into the woods a few weeks ago for a test and the locker performed flawlessly which leads me to believe everything was installed correctly.

The only other thing I can think of is that maybe my caliper/s is seized. I have a 5 mile ride home from work with very few stops and both front wheels are really warm by the time I get home. I'm debating whether I should throw some new calipers on this weekend to see if that fixes the problem.

Anyone have any ideas on what could be going on?

 

[cwstnsko]

By hubs, do you mean unit bearings? Is it possible that you got unit bearings that were a different geometry than the ones you replaced and now the brake rotors are not centered in the caliper and dragging on one side

 

[XJLI]

dragging brakes FEEL like dragging brakes. i seized 3 calipers on my old XJ... one was a smokeshow, the others just felt like someone was holding the truck back.

if you do brakes and the caliper pistons are hard to press back in, theyre shot.

 

[ktm racer 419]

jack up the axle and see if the wheels have any significant drag

 

[asp]

If you got hubs for the wrong generation of rotors, you'll be clamping your brake pad against the inside of the rotor when you put the wheel on.

 

[OverlandZJ]

If you got hubs for the wrong generation of rotors, you'll be clamping your brake pad against the inside of the rotor when you put the wheel on.

This..

Still have your old hubs? Measure the depth from where it mates to knuckle to rotor mating surface on old and new.

 

[Trailboss]

If you got hubs for the wrong generation of rotors, you'll be clamping your brake pad against the inside of the rotor when you put the wheel on.

I'll check this out tomorrow. I ordered Timken hub assemblies from my cousin who owns an auto parts store. I assumed he would have gotten me the rights hubs but it's possible they may not be. Thanks for the help everyone.

 

[asp]

http://www.naxja.org/forum/showthread.php?t=101343

Do all brakes and hubs interchange on Dana 30’s?

Answer:

Basically, there are three rotor/hub/knuckle combinations. The early style that MOSTLY came on disconnect housings, the late style that came on non-disco housings, and the latest style that came on low pinion housings.

The early style brakes can be identified by the 7mm allen-head studs that retain the caliper to a two-piece knuckle. These are generally spec’d on 84-90 vehicles.

The two later style uses a standard headed bolt to retain the caliper to a one piece knuckle.

The only difference in the two styles is the spacing, but it means you can’t mix and match rotors from the various styles. Axle shaft lengths are the same, so you can plug in late model shafts into your early housing with no problem. Also, if you want to use the late model hub/rotor/knuckle combo, you can bolt them to your early housing without trouble.

For reference, the unit bearing and rotor combo according to the year breaks is:
89 and down
90-2000
2001

seen here

I'll check this out tomorrow. I ordered Timken hub assemblies from my cousin who owns an auto parts store. I assumed he would have gotten me the rights hubs but it's possible they may not be. Thanks for the help everyone.

Sounds like we found the problem, then. Good luck.

 

[Trailboss]

This..

Still have your old hubs? Measure the depth from where it mates to knuckle to rotor mating surface on old and new.

Passenger side was still in decent shape so I kept that one for a spare. Will def measure tomorrow.

 

[Trailboss]

Just to confirm. The hub assembly part number that I need is Part # 5016458AA?

 

[asp]

Just bring your old one to your cousin and compare the 3 on the shelf. Get the one that matches your old one, and save its box.

 

[Trailboss]

Turns out the driver side caliper was hungup. Replaced it on Sat and no more sluggish feeling. I checked the hub assemblies and they are the right ones. Thanks again for your help guys.

 

[kastein]

http://www.naxja.org/forum/showthread.php?t=101343



For reference, the unit bearing and rotor combo according to the year breaks is:
89 and down
90-2000
2001

seen here


Sounds like we found the problem, then. Good luck.

just for completeness... those year breaks are wrong. It's 89-down, 90-99, and 99.5-01. The 99.5-01 ones are the same as TJ unit bearings for 97-whatever IIRC.

 

[asp]

Ah. My mistake.

Glad the problem got taken care of :thumbup: